1. Field of the Invention
The present invention relates to a socket contact. In particular, it relates to a structure of a socket contact mounted to a print substrate, in which the socket contact is constructed to be a female contact configured to couple with a male connector of a blade form.
2. Related Art
For example, it is possible to attach a plug to a terminal of an electrical wire, attach a receptacle to a print substrate, removably couple these connectors, and electrically connect the wire to the print substrate. Such a connector is referred to as a so-called “Wire to Board Connector.”
Furthermore, it is possible to attach a plug to one print substrate, attach a receptacle to another print substrate, removably couple these connectors, and electrically connect the pair of print substrates. Such a connector is referred to as a so-called “Board to Board Connector.”
In addition, usually, male contacts are placed in plugs and female contacts are placed in receptacles.
In recent years, along with small electronic apparatuses, plugs and receptacles have also become small. Furthermore, in connectors that connect a connector having pin contacts (male contacts) and a connector having socket contacts (female contacts) which clamp these pin contacts, socket contacts of small size which nevertheless have high clamping power and spring resistance have been invented (for example, see Japanese Unexamined Patent Application Publication No. H7-169523 (hereinafter referred to as “Patent Document 1”)).
The socket contact according to Patent Document 1 forms an embossed portion that stretches along a pair of beams which are leaf spring form members, from a vicinity of a region of contact to a fixed end. Furthermore, a depth D2 of the embossed portion is made deepest in a vicinity of the fixed end, and a depth D1 of the embossed portion is gradually made shallower as the same extends along the top of the region of contact, or the fixed end.
The socket contact according to Patent Document 1 is described as made to be able to raise a second moment area of the vicinity of the fixed end of the beams in achieving spring strength. Furthermore, the socket contact according to Patent Document 1 is described as lessening the second moment of area toward the fixed end or the region of contact, and being able to avoid convergence of stress and to disperse the same.
The socket contact according to Patent Document 1 provides a terminal extending in a direction orthogonal to an insertion direction of pin contacts on a fixed end of one of the beams. In addition, this terminal is inserted into a through hole provided on the print substrate, and soldered. That is to say, the connector having a socket contact according to Patent Document 1 achieves a print substrate connector.
Incidentally, for this kind of print substrate connector, SMT (Surface Mount Technology), in which a lead portion of a contact is joined by soldering to a print substrate, is becoming common in replacing through hole mounting.
In SMT, because there is no need to provide through holes in the print substrate, it is possible to narrow a central pattern clearance, and to equip electronic components having leads of a narrow pitch. Moreover, SMT has a merit in that double-sided mounting is made possible, and thus can increase mounting density.
However, if the terminal of the socket contact according to Patent Document 1 is converted to a lead for SMT, when the pin contacts are inserted, there is the problem in that a force acts to strip the lead from the print substrate by a bending moment acting thereon.
Furthermore, there is the problem in that, when a blade-shaped male contact instead of a pin contact is inserted into a pair of beams, since the friction resistance increases greater than with the pin contacts, a bending moment acting on the lead increases, and the force stripping the same from the print substrate increases still further.
That is to say, a small-size socket contact that surface mounts to a print substrate is sought such that, even if a blade-shaped male contact (hereinafter called a “blade contact”) is inserted therein, detaching at solder of the small-size socket contact from the print substrate is difficult. The above can be said to be the topic of the present invention.